1. Field of the Invention
The present invention is related to an input device and, especially, to an input device with a dynamic display function.
2. Description of the Prior Art
A lock is an old invention for protecting people's properties and physical safety. A traditional key-lock pair is improved as a key-less electronic lock to prevent a duplicate of a stolen key. A conventional electronic lock has buttons to input a preset password for unlocking. The buttons usually contain ten digital numbers from “0” to “9” being sequentially placed at a fixed position on the electronic lock. Since the buttons are fixed, the lock owner always presses the same buttons when inputting the password. This will lead to fingerprints or marks being left on surfaces of those buttons. Thus, the password of the electronic lock becomes easy to guess by other persons if they try to break into the lock owner's properties. Because certain buttons are always being pressed, it is also hard to prevent the password from being guessed by peeking or being secretly recorded by other persons.
In order to solve the disadvantages of fixed buttons of the conventional electronic lock as described above, a liquid crystal display (LCD) for displaying digital numbers has been utilized. The same digital number will be randomly displayed in a different position on the LCD in every operation. Thus, fingerprints or marks won't be left on the conventional electronic lock. However, the electronic lock with an LCD consumes too much power and needs to be charged or batteries must be changed frequently.